The present invention relates to the use of a vacuum bulb in combination with a valveless vacuum duct added to a siphon tube as a means for initiating a fluid flow from a primary aquarium to its auxiliary filter tank.
The prior art has seen the use of vacuum bulbs as permanently affixed elements of relatively complicated aquarium and other types of fish tank systems.
For example, see U.S. Pat. No. 3,549,015 to Willinger; U.S. Pat. No. 3,584,602 to Stossio; and U.S. Pat. No. 3,734,853 to Horvath.
Each of the above patents disclose use of siphon bulb as a fixed and permanently incorporated element of a larger fish tank system. Because of the permanent nature of the siphon bulb in said references, it is noted that it has been necessary to provide such bulbs with a variety of different valves and filter arrangements in order to make them fully functional within the contexts of their prior art use. That is, prior art usages of siphon bulbs have occurred in association with moving parts, such as valves and tubes which have been required because of the fixed, non-detachable nature of such bulbs, valves that can get dirty and malfunction and interfere with the cleaning of said valves and tubes.